Alex looked through the runes, biting his lower lip. He had no idea what to pick, and the voice clearly wasn't going to guide him. He saw one image that looked like a set of scales, and he was a Libra so maybe that was a good enough pick. He reached out and his finger brushed the rune, causing it to ripple.
"Interesting." The voice almost purred the word. "The Boon of Exchange, that's one of my favorites, though not many pick it. I guess the rune is too bland looking." Alex could almost hear the voice smirking.
"Simply, you can exchange any physical attribute with another being of this world. It can be a small detail, or a nearly whole body alteration. You get theirs, they get yours. Though there are limits. First you must be able to think of the attribute as a simple whole. Hair color will work, so would hair, or head hair, facial hair, body hair.. however you want to narrow it down. But two items you can't think of as a whole such as say a beard and their height won't work. Second, you can only make an exchange with any given individual once."
"Once? So once I trade something away..?" Alex lets his words drift off.
"There's no getting it back. Correct. Though if you can find similar elsewhere, you can trade again. I will even give you a bonus, you can decide who if anyone notices the changes." The Rune shimmered and moved towards Alex, it slowly floated down towards his right hip where it sunk into the skin, leaving an image of itself behind.. Alex prodded the new tattoo which would just be covered by his pants. If he even got any.
"Amuse me, and I may be willing to grant you more boons." The voice sounded way too pleased.
The room snapped back into existence around Alex, and he stood one more staring at himself in the mirror. The only change being the tattoo that he now sported. "Not a dream." He muttered as he poked at it. "Maybe I could give it a try?" He walked over to the window and looked at a few of the people walking down the street.
One man caught his eye quickly. He had short hair, but it was a bright coppery-red. He looked at the man and chewed his lip. "Think it I guess?" So he focused and thought 'hair', also wishing for no one to notice the change. The man's hair lengthened a couple inches and turned brown. Alex was about to run to the mirror but stopped as his chest suddenly itched. Alex had never been a hair guy, but now a light dusting of red hair was growing out along his chest, and down his stomach to where even his pubes were a fiery red. He ran back to the mirror and say that man's short-styled hair cut in the right color atop his head, some stubble on his jaw, too. Lifting his arm he eyed the red bushed in his pits. "Guess hair wasn't very specific. Not a bad look though." Alex ran his finger tips through the hair on his head, even the texture of it felt a little different.
Something else in the mirror caught his eye, there was stuff sitting on the previously empty table. He went over to check it, unfolding a pair of trousers and a vest that looked a little too small, but he realized it was after the local fashion, more decoration than covering and meant to show off skin. Boots, and a belt with a knife and a pouch. The pouch jingled softly and Alex opened it to find a handful of coins of various types. He didn't know how much it was but there were more than a few bits of gold. Still, it wouldn't last forever.
He needed to figure out how he was going to live in this world. Or maybe he could play a bit more first, he thought, bouncing one of the gold coins in his hand.